In 2013, researchers excavating a convent in Rennes, France dug up a 450-year-old lead coffin. Inside, they found a strikingly well-preserved body, wearing leather shoes and swathed in religious cloaks.

They also found something else—another, much smaller lead box, in a familiar shape. When they opened it up, there was a human heart inside.

As National Geographic reports, the body was that of a 17th century noblewoman, Louise de Quengo. The heart belonged to her husband, a knight named Toussaint de Perrien.

Historians already knew that European aristocrats were occasionally buried apart from certain of their body parts, generally for political and religious purposes—to maximize prayer sites, or, if the deceased perished far from home, to pay fealty to their country.

But according to new research from France's National Institute for Preventive Archaeological Research, Louise and Toussaint are the only dead couple on record to have done it for love.

"Toussaint de Perrien died in 1649—seven years earlier than Louise—and was buried 125 miles away" from her home in Rennes, National Geographic writes. But first, his heart was cut out and stashed in the lead container. Louise hung onto it until she died, too, and then she literally took it with her to her grave.

There's another piece to the puzzle: when researchers performed a CT scan of de Quengo's body, she, too, was missing her heart. They figure Touissant probably has it. Happy Valentine's Day, everyone.